1. Technical Field
The present invention relates generally to a surge protection apparatus and a method using the same, and, more particularly, to a surge protection apparatus and a method using the same, which blocks a high power surge or a high energy surge for a long time period.
2. Description of the Related Art
Generally, when a surge greater than rated voltage or current flows into an electricity/electronic apparatus, the electricity/electronic may malfunction or be damaged. Here, a surge is a pulse created by an instant and sudden large increase in voltage or current.
Surges are normally generated because of lighting and a sudden load change, and are generated when a High Altitude Electro-Magnetic Pulse (HEMP), obtained when a nuclear device is exploded at an altitude of 30 km or higher, is coupled to a power cable or a communication cable.
FIG. 1 illustrates the conditions of a Pulse Current Injection (PIC) test that commercial power cables of facilities are subjected to in conformity of MIL-STD-188-125-1 which is the military standard of the United States of America related to HEMP protection.
Referring to FIG. 1, a current of 10 A or less should flow through a load resistor when a high power short pulse is applied, and performance degradation or physical damage should not occur when high energy intermediate pulse or long pulse is applied.
Generally, in order to block the inflow of a surge, a surge protection apparatus is provided at the front end of a specific circuit, and a filter is provided at the rear end of the circuit, so that the component of a surge which is equal to or greater than a set value is first blocked using the surge protection apparatus, and then the unnecessary remaining component of a frequency band is removed using the filter.
Prior art surge protection apparatuses include non-linear elements, such as a varistor, a gas discharge tube and a transient voltage suppression diode, in which resistance rapidly decreases when the difference in voltage between the two ends of such a surge protection apparatus is equal to or greater than a preset value.
Such a surge protection apparatus may effectively block a high power surge such as a short pulse. However, in the case of a high energy surge persisting for a long time period, such as an intermediate pulse or a long pulse, there are problems of performance degradation and physical damage because a non-linear element is overheated or electrodes are damaged.